Figure 1.

EGFR is part of a family of receptor tyrosine kinases (RTKs) that also includes HER2 (ERBB2), HER3 (ERBB3) and HER4 (ERBB4).

Notes: These RTKs comprise a ligand-binding extracellular domain, a transmembrane link and an intracellular catalytic domain. Binding of growth factors to the extracellular domain leads to homo- or hetero-dimerization of the respective receptor, with subsequent activation of RTK activity and regulation of multiple key intracellular signaling substrates as shown in the Figure.

Abbreviations: EGFR, epidermal growth factor receptor; HER, human epidermal growth factor receptor.